The fundamental study of coupled thermal–hydraulic-mechanical (THM) systems is an important issue in multi-physical fields. This study developed a THM model in which the hydraulic and mechanical effects are fully coupled and the temperature change serves as the perturbation source of the system. A porothermoelasticity model was applied to investigate the cross-interactions among the temperature, change in pore water pressure, and displacement of a buffer material in the near-field and a host rock in the far-field with the conceptual model in a nuclear waste repository. The results show that the size scale of the domain of interest and the THM properties play important roles in the coupled THM system. The changes in pore water pressure depended on the combined effect of the deformation of the porous space and pore water controlled by the thermal expansion coefficients of the solids and fluids. Stochastic analyses show that the uncertainties of variables varied spatio-temporally due to the thermal influences and approached zero due to the presence of a stable condition. The cross-interactions between displacement and change in pore water pressure induced by the thermal effect were complex and can be determined from statistical moment analyses.

热－液压－机械（THM）系统的基础研究是多物理领域中的重要问题。这项研究开发了一个THM模型，在该模型中，液压和机械作用完全耦合，并且温度变化是系统的扰动源。应用多孔弹性模型，利用概念模型在核废料库中研究温度，孔隙水压力变化以及近场缓冲材料和远场基质岩石之间的交叉相互作用。 。结果表明，感兴趣的域的大小尺度和THM属性在耦合THM系统中起着重要作用。孔隙水压力的变化取决于由固体和流体的热膨胀系数控制的多孔空间的变形和孔隙水的综合作用。随机分析表明，变量的不确定性由于热影响而在时空上变化，并且由于存在稳定条件而接近于零。由热效应引起的孔隙水压力的位移与变化之间的相互作用是复杂的，可以通过统计矩分析来确定。